肺心病急性发作期患者的组织氧合状态及机械通气对其影响

目的观察慢性阻塞性肺疾病（ＣＯＰＤ）所致肺心病急性发作期合并Ｉ型呼吸衰竭患者机体组织细胞的氧合状态及机械通气对其影响。方法利用胃粘膜组织内ｐＨ（ｐＨｉ）技术测定１９例ＣＯＰＤ所致肺心病急性发作期合并Ｉ型呼吸衰竭患者机械通气前后及脱机前后ｐＨｉ的变化。结果发现机械通气前ｐＨｉ的三次结果分别为７．１８±０．０６，７．１９±０．０４，７．１８±０．０６，均明显低于７．３２；行机械通气后ｐＨｉ逐渐上升，４天后＞７．３２；脱机前及脱机后ｐＨｉ变化不明显。相关分析显示ｐＨｉ与动脉血ｐＨ（ｐＨａ）、硅胶囊内二氧化碳分压（ＰｇＣＯ２）与动脉血二氧化碳分压（ＰａＣＯ２）无相关性（ｒ＝０．３５２和０．４２１，Ｐ均＞０．０５），提示ｐＨｉ的测定不受合并高碳酸血症的影响。结论肺心病急性发作期合并Ｉ型呼吸衰竭时存在组织氧合不良。ｐＨｉ的测定对指导临床治疗具有十分重要的意义，并有可能作为指导撤机的一项指标。

The tissue oxygenation status and the effects of mechanical ventilation on oxygen dynamics in COPD patients with hypercapnia

OBJECTIVE: To assess the tissue oxygenation status and the effects of mechanical ventilation (MV) on oxygen dynamics in COPD patient with hypercapnia. METHODS: Gastric intramucosal pH (pHi) measured by gastric tonometer was examined in 19 patients before and after MV. RESULTS: pHi calculated before MV was 7.18 +/- 0.06; After receiving MV, pHi increased gradually until above 7.32 in 4 days; during weaning, there were no significant changes in pHi before and after discontinuation. The correlation analysis showed that there was no correlation between pHi and pHa (r = 0.352, P > 0.05), PgCO(2) and PaCO(2) (r = 0.421, P > 0.05), suggesting that pHi measurement would not be affected by hypercapnia. CONCLUSIONS: Our study showed that tissue oxygenation insufficiency existed in COPD exacerbation stage. Gastric pHi may be used as the parameter to estimate tissue oxygenation status and a predictor of weaning from mechanical ventilation.